Dentifrices used for oral hygiene generally includes three different types of paste, classified according to hardness (hard, medium and soft). The structure of these pastes is not comparable to a conventional toothpaste. Rather, it is similar to a polishing paste whose consistency is nearly crumbly. This crumbly structure is necessary when the dentifice is used in the buccal cavity with a polishing device in order to avoid loss of substance by e.g. spraying. These pastes are used by dental hygienists as a supplement to daily dental care in order to remove stubbornly adhering dental plaque. This additional treatment is intended to support oral hygiene in such a manner that caries are reduced, thus rendering dental treatment almost superfluous. Experience has shown that a cleaning every two months is necessary for a good effect. The minimum frequency for this type of care is twice a year.
When carrying out the additional care, the dental hygienist first treats the plaque with the hard paste, then with the medium-hard paste and finally with the soft paste. A roughening of the tooth surface is sought with the hard paste, in order to embed the fluorocomponents of the dentifrice so as to obtain a long-lasting action in this rough surface. The medium-hard and the soft pastes are intended to polish away the coarsest unevenness on the tooth.
Known dentifrices for preventative dental hygiene prophylaxis also contain pumice, zircon silicate or hard Al.sub.2 O.sub.3 in addition to silicates. This makes it possible to achieve RDA values of 250 (hard paste), 120 (medium-hard paste) and 40 (soft paste). Tests have shown that the copper abrasion of these three variants is relatively high at 70-100 mg Cu, but not very different.